Holiday congestion is already starting to build on Auckland's Southern Motorway with journey times heading out of the city already taking up to three times longer than usual.
At 3pm, journeys on State Highway 1 between Mt Wellington and Manukau were taking 22 minutes instead of the usual 7.5 minutes and from Hobson St to Manukau were taking 40 minutes instead of 18 minutes, according to AA Traffic.
There is also heavy traffic at Auckland Airport and motorists have been asked to allow extra time for travel.
A crash at on State Highway 29 between a light truck and the car closed the road at the Kaimai Range this afternoon.
One person has life-threatening head injuries and another has serious injuries following a car and truck collision shortly before 2.14pm today.
The other two occupants of the car have moderate injuries and the condition of the truck driver is not known.
The road was closed, but has since reopened.
The Automobile Association's general manager of motoring affairs, Mike Noon, said with sunny, clear conditions forecast for most of the country people needed to take extra care in the mornings and evenings.
"The low winter sun can make sun-strike a real problem at either end of the day and the clear conditions mean there will likely be some frosts and icy roads in places."
From May through to August is the worst time of the year for sun-strike crashes which normally involve a driver pulling out in front of a vehicle they didn't see or rear-ending a vehicle stopped in front of them.
Mr Noon said the fine weather was also likely to mean a lot of traffic on the roads this long weekend, so drivers should expect some delays and try to avoid travelling at the peak times of Friday afternoon, Saturday morning and Monday afternoon if possible.